Noninterfering alarm box



3 Sheets-$heet l S. W. ALDERFER NONI NTERFERING ALARM BOX Filed Oct. 8, 1927 April 28, 1931.

ATTORNEYS.

April 1931- s. w. ALDERFER 1,803,277

NONIINTERFERING ALARM Box Filed 001;. a, 1927 5 Sheets-Sheet 2.

V INVENTOR. 5 57091111 hf rim/ewe BY I ATTORNEYS.

A ril 28, 1931. s, w, ALDERF R 1,803,277

NONINTERFERING ALARM BOX Filed Oct. 8, 1927 3 Sheets-Sheet 3 I N V EN TOR. 5 751% m; W 4: 052m ATTORNEYS.

Patented Apr. 28, 1931 sra'rss raren'r OFFICE s'rnnmne w. nr-nnnrnn, on AKRON, onro, ASSIGNOR TO THE GARL SIGN AL COMPANY,

or AKnon, 03110, A conroaarionoronio NONINTERFERING ALARM :Box

Application filed (lctober 8, 1927.' Serial N'o. 224,889.

This invention relates to the art of electric signalling, particularly to systems of signalling used in fire alarm circuits, although it is not necessarily confined to that i particular art, but may be employed for other purposes and in other capacities.

The particular object of the present invention is to design and construct an alarm system or an alarm box of the non-interfering 1 type, that is, one in which a series of boxes or stations are arranged in series upon asingle line, and in which mechanism is provided so that the transmission of a signal from one box or station'on a line will not interfere with a signal which is being transmitted from another box. In alarm systems, if one box upon a line is pulled and the alarm is being transmitted, which consumes a period of time, owing to the necessity of repeating the box number, a second box on the same line may be pulled. In non-interfering alarm systems, to, which this invention res lates, the pulling of a second box will not interrupt or interfere with the transmission of the signal-from the first box, but the alarm from the second box will be delayeduntil the first box completes its cycle, and the second box will then'come into action to transmit its own signal without attention on the part of terference by the first box.'

Non-interfering systems have been known heretofore, but thesystems as designed heretofore are quite complicated and are easily put out of order. The present invention is designed to simplify this type of system and to construct and perfect an accurate, mechanthe person operating the second box, or inthe drawings and description are quite detailed, the broad principles of the invention may be embodied in different forms and structures, and the claims are intended to coversuch variations or modifications as may be fairly. held to fall within their. scope and within the true scope of the invention as set forth herein. I

In the drawings, in which the present known and preferred form of the invention is shown Figure 1 is a front elevation of the mecha nism. incorporated in a single box in a. fire alarm system showing the front of thebox where the non-interfering mechanism is located;

Figure 2 is a plan view of the parts shown in Figure 1;

Figure 3 is an enlarged section on the line 33 of Figure 1;

Figure t-is an enlarged detail of the non-.

interfering mechanism, the box being in the position of rest; -Figure 5 is an enlarged detail of the pivot for the shunt lever; and

Figure 6 is a diagrammatic view showing the manner of connecting a series ofthe boxes.

in a line together with the connections at headquarters.

The views show the complete self-contained" mechanism which is mounted in a box, the casings andother fittings common to alarm boxes being omitted. Each unit is mounted upon a base plate2 having a vertical face ,or wall 3, preferably-of semicircular construe? tion to fit the standard pole box used in mu.- nicipalities. Upon the rear of the wall 3 is secured the usual clock mechanism 5. which houses the coil spring drum 6, adapted to be wound by the key 7 projecting outwardly of the plate and operating through pinions 8.

gear train 10 is operated from the spring,

having the usual regulating and escap'ement mechanism, as is standard in all boxes of th s type and need not be described in detail.

The last of the gear train'is secured to. a shaft12which projects through the face 3 and carries the code wheel 14, the outer periphery of which is notched or provided with teeth 15 to correspond with tlu number of the box, these teeth being arranged in groups or sets of the numbers required for the particular system. The code wheel, shown in Fig ures 1 and 4, is intended for the box number 426, this number being repeated four times about the wheel, and runs in the direction of the arrow X. On the wheel, just prior to the first group of teeth is located an elevated blank sector 16, which provides a period in the rotation of the wheel which may be described as a feeling period during which time the box is operated to determine whether or not another box in the same line is sending in an alarm. The operation of this portion of the code wheel will be described more fully later.

The face of the code wheel is provided with a circular wall or flange elevated above the wheel, this wall being continuous except in the sector opposite the sector 16 and at a point lying within the first signalling group. -As the wall approaches the sector 16 it is cut down, as shown, to provide a thin web 22 which terminates at the beginning of the feeling sector. Immediately following this point is arranged a transfer device in the form of an inclined lifting cam 23 extending from the outer edge of the disk to the inner line of the flange 20, from which point the wall is broken to provide a gap 24. Shortly thereafter the wall is cut away again to pro-' vide a second short gap 25 which is located at some point within the first signalling anchored at its inner end to the face of the wheel as shown at 36. The outer end of the block is provided with a book 38 which lies closely adjacent the end of the web 22. The rear of the block is provided with a pin 39 which projects through a slot 40 in the code wheel 14' and lies within the pathof a vertically movable plunger 42, by which it is to be elevated. The plunger is guided-at its upper end in a block 43 attached to the wall 3,

and at its lower end in the base plate 2, being pivoted at its lower end to an operating lever 45, rocking in an angular bracket 46 secured to the underside of the plate 2. The outer endof the lever is provided with an operating knob 47 and the plunger is maintained at its lowermost point by a spring 50. When the person operating the box pulls the knob 47 downwardly, the upward movement of the plunger releases the code wheel momentarily,

sufficiently to allow the wheel to commence its rotation under the influence of the clock mechanism and to continue until it completes a single effective ringing cycle.

On the face plate 3 is mounted a shunt lever 55, this arm being pivoted on one side of the face plate upon a pin 56 and retained by abolt'57 (Figure 5). The pin is secured in position by a bolt 58 passing through the plate 3. The arm is insulated from the plate by fiber washers and bushings 60. The bolt 58 serves as a binding post for a shunt wire 61 leading from a main binding post 62 in the base plate to a double electro-magnet 64 mounted in a bracket 65 in the upper portion of the face plate. Electrical connection from the pin 56 to the arm 55 is maintained through flexible wire 66 connecting the bolt 57 and the arm.

' The arm55 passes just below the wheel, at which point it is provided with an insulating bracket 68 from which projects a pin 69 adapted to ride within or outside of the wall 20. When the pin is riding upon the inside of the wall, the outer end of'the shunt lever is in close relationship to the magnet 64, and the armature 70 carried by the lever and passing through an opening 71 in .the face plate is attracted and held by the. magnet, vif it is energized. When the magnet is not energized, the shunt lever will fall, provided the pin 69 is opposite any of the gaps in the wall, until its outer end rests upon a stop pin 7 2 mounted on the top of a vessel providing a mercury bath 73 secured to the face plate. When the parts are at rest with the pin 66 outside the web 22, the armature is out of contact with the magnet and removed to such an extent that it cannot be attracted thereby. The lever 55 is provided with a pin 7 5 which dips in the mercury bath pot, making electrical contact therewith.

Starting with the parts at rest, a shown in Figure 4, the wheel is held from rotation by contact of the pin 69 with the. hook 38 on the stop block 30. If the knob 47 be de pressed, the plunger 42 will raise the catch or stop block and the wheel will be released, whereupon it immediately starts its rotation. The cam surface 23 elevates the pin and the shunt lever until the armature is brought in close contact with the magnet, where it is retained, if the current is flowing continuously through the magnet during the operation of the feeling sector 16 and until the pin 69' is within the wall 20. If the current through the magnet is interrupted while the pin 69 is passing over the gap 24, the pin will fall through the gap, but if the current is maintained, it will pass over the gap and the wheel will continue its rotation until stopped by the contact of the pin 69 with the catch 38.

The alarm is transmitted to the central oflice through the code lever 80 which is pivoted upon the wall plate at 81', being pressed upwardly by a coil spring 82 bearing against the underside of the lever and against a bracket 83 in the wall plate. Immediately below the code wheel on the lever 80 is secured an insulating block 85 in which is mounted a pin 86, held in contact with the rim of the code. wheel and through which the teeth upon the wheel actuate the lever to make and break the alarm circuit and thereby transmit the alarm. The end of the code lever is provided with a pin 87-which dips in the mercury pot 7.3, so that both contacts are made through a single pot; The advantage of making both contacts through a single pot lies in the fact that loss or removal of the mercury from the pot would immediately show up at the central oflice or headquarters since the shunt circuit would remain open. If separate mercury pots were used, and that of the shunt circuit were intact and that of the alarm circuit were open, the alarm box would appear to be operative at headquarters even though the box would not be capable of serving its purpose when an alarm was turned in.

Referring particularly to Figure 6, which shows two boxes upon a circuit, the lower box A. (No. 426) is shown sending in an alarm, while the upper box B (No. 425) is in its normal condition. The circuit passes from the battery 90, through the signalling relay 91 at headquarters, and through a telephone set 92 to the main line 93 which is connected to binding post 94 on the box A. From the post 94 the line 95 passes to the mercury pot 7-3. At this point it is provided with. two paths, one of which is a shunt through the shunt lever direct to the binding post 62 and thence to the line 96, if the lever 55 is lowered, and the pin 75 in the mercury pot. If the lever 55 is raised, the current passes through the code lever 80 and line 97 to the solenoids 64 and out through the line 61 to the binding post 62, the circuit through this lever being made and broken by the rotation of the code wheel. Before the line 96leaves the box, it passes through a telephone post 98 with which a removable telephone jack 99 carried by the line man may be inserted in the circuit for communication with headquarters through telephone 100 located at that point. The circuit then passes through a telegraph key 101 and into the box B, being connected to the binding post 94 on that box. The number of boxes in a single circuit may be increased to any practicable extent and the telephone and telegraph devices may be used if desired.

Having described the construction of a single box, a detailed description of the operation of the circuits will explain the manner in which the non-interfering system is rendered operative.

It will be observed that the box is normally on a closed circuit from line 93 through post 94 to mercury cup 73, through shunt lever 55 to post 62 to which is connected line 96.

Assuming that the partsare as shown-in Figure 6, a person desiring to send in an alarm stop 72. The inclined cam track 23 then picks,

up thepin and elevates it with the shunt leveruntil'the armature 70 is in contact with the solenoids 64. As the code wheel continues its rotation, the sector '16 will depress the code, lever and the circuit will be established through the line 97 and the magnet V which is energized and thereby retains the lever 55. At the end of the revolution, the

pin 69 is caught by the block 30 and the wheel is againv locked in position.

If, however, an alarm is being sent in from another box on the line, the circuit will be interrupted by the operation of the shunt lever 55in the other box, and the armature will be released through the de-energizing of the magnet 64'and the pin 69 will fall through the gap 24, riding about on the outside of the wall 20 untilit is again picked up by the cam 23. If the other alarm has been completed during the idle revolution of the code wheel, the energizing of the magnet will take place and the wheel will continue its revolution with thepin inside the wall 20. If the other alarmisstill being sent, the wheel will continue its revolution until the pin 69 is finally caught and held in its uppermost portion,

whereupon the wheel will revolve for a'full active ringing cycle 'and'then stop by contact of the pin and the catch 38. The magnet constitutes a temporary detent for the shunt lever 55, which detent is releasable by current interruption from other boxes in the ringing circuit.

The-gap 25 is provided as an additional measure of precaution in case two alarms in the same line were turned in simultaneously, whereupon both boxes might operate to pass the pin over the gap 24, but due to difierent timing of the strokes of the several alarms, one of the boxes would be rendered inefiective by release of the pin 69 as it .pass'es'over the gap 25. It is extremely improbable that two boxes on the same line would be pulled at close enough intervals so that the feeling period allowed bythe sector 16 would not operate, but in case sucha condition did occur, it would be corrected at the point 25. The gap 25 is of such dimension and so placed that the shunt lever pin can pass through the same only at a' point opposite to a code wheel tooth on the same alarm device whereby the operation of the code lever on the same alarm device will not cause the device to idle.

. It will be observed that while the box is at rest, as shown at B, or while the code wheel is rotating with the pin 69 outside the wall 20, the pin 7 5 on'the shunt lever is in the mercury pot and the current flows through lever 55, so that while the code lever 80 is moved by the index wheel, the flow of current through the line is not interrupted and the signal from the other box will not be interfered with; i

It will be noted that pins 75 and 87 are adjustable so that they can be accurately set to contact properly with the mercury in the pot 73, and that the pin 7 5 is slightly lower than the pin 87 so that when the box is not r in operation, current will always be assured through the shunt by means of the lever 55. It will also be noted both pins are located in a single pot so that the current through the shunt and through the ringing circuit is completed through the single mercury pot.

The device which has been described affords an accurate and positively acting, noninterfering alarm box. In a circuit, as has been described, the sending of a signal from one box will not be interfered with if another box is pulled while the first is ringing, but the second box will continue to op erate idly until the first has completed its alarm, whereupon the second will then take up the circuit and send in its alarm until completion.

Having explained the mechanism. as embodied in the alarm box forming the subject of the invention, it is obvious that variations and modifications may be made without departing from the invention. It is possible to utilize the principles of the invention in boxes and mechanisms specifically different, and such other devices are intended to be covered within the fair scope of the appended claims.

lVha-t isclaimed is 1. A non-interfering alarm box, comprising a main alarm circuit passing through the box and divided into parallelcircuits within the box, one of the circuits being an alarm circuit including alarm mechanism and the other a shunt about said mechanism, a movable switch forming apart of the alarm circuit and a second movable switch forming a part of the shunt, said switches being independently operable, said alarm mechanism including a code wheel having formations thereon for operating the switches in the code circuit and shunt, means operable by making or breaking the code circuit to hold the shunt switch in or release it from its open position, and a single mercury pot in which the switches dip to complete the circuit.

.2. A codev wheel for the uses and purposes set forth, comprising a portion with designating formations thereon, a wall upon the face of the wheel, an inclined cam from the outside of the wheel to the inner surface of the wall, the wall being provided with a gap adjacent the inner end of the cam, and a releasable catch located at the end of the wall.

3. A code wheel for the uses and purposes set forth, comprising a portion with designating formations thereon, a wall upon the face of the Wheel, an inclined cam from the outside of the wheel to the inner surface of the wall, the wall being provided with a gap adjacent the inner end of the cam, and a releasable catch located at the end of the wall, in combination with a switch having a portion which may ride upon the wall as the wheel is rotated.

STERLING W. 'ALDERFER. 

